US1865003A - Electric welding tong - Google Patents

Description

June 28, 1932; c. E. HALL ELECTRIC WELDING'TONG Filed Apg. 2, 1929 /H.WIM w I Invsn'roR I Patented June 28, 1932 [UNITED STATES PATENT OFFICE CARLOS E. HALL, OF BED MOUNTAIN, CALIFORNIA ELECTRIC WELDING- TONG Application filed August 2, 1929. Serial No. 383,006.

My invention relates to improvements in s ngle electrode welding tongs whereinone s1de of a direct current circuit is grounded to the work while the other side is connected thru a flexible power cable to the tong which holds the welding material.

Ordinarily, during the operation of welding, it is not feasible to turn the current off and on at the motor generator since the leads 10. are long and the welding work is done at quite a distance from the generator. It is necessary and convenient, from time to time during the work,-to lay aside the tongs, and

. if, in doing so, they come in'contact with the ()ne of the objects of my invention is to provide contacts within the body of the andle of the tong which will disconnect the tongs and all protruding metal parts from the power cable lead. Another object is to provide means whereby the contacts will remain in open position until positive actuation of the separation means by the operator. A further object is to provide contact elements, conveniently situated, within the o handle body of the tong, capable of handling a large current of electricity without overheating or burning. Other objects will appear hereinafter.

I attain these objects by the device illustrated in the accompanying drawing 1n which: t

Figure 1 is an assembled View of my 1mprovedtong, being in vertical elevatlon, and with the handle portion in section; Fig. 2 1s a section of the tong supporting rod on line 22 Fig. 1; Fig. 3 is a section of the locking ring on line 3-3, Fig. 1. Fig. 4 is a perspective view of the locking ring.

Similar numerals refer to similar parts throughout the several views.

The welding bar gripping tong is composed of the stationary jaw 1, and 'the movable jaw 2, connected by hinge bearing 3 and held closed by sprin 4. The lower portion of sta-' tionary jaw 1 orms a conductor bar 5, upon which is formed the flange 6 having on its under side two oppositely positioned lugs 7. Below this flange the conductor bar is shaped into a cylindrical rod 8, which extends from between the lugs 7 through locking ring 9 into the hollow cylindrical handle 10. At its lower end the rod 8 is brazed into the conical contact element 11. The open spring 12 surrounds rod 8 Within handle and bears against ring 9 at its'upper end and against the upper side of contact element 11 at its lower end. With* in handle 10 and positioned below contact 11 is a cylindrical contact 14, on the lower end of which the rod 15 is formed. This rod extends throu h the insulating ring 16 and at its lower cm? is threaded to receive nut 17 and the power cable connecting sleeve 18. Ring 16 is held in place by screws 26 extending through handle 10.

The lower side of the contact element 11 is tapered to form a contact surface 19 in the shape of an inverted cone. round and easily movable within handle 10 forming a guide for the lower end of rod 8. The upper side of contact element 14 is hollowed out so as to form a conical opening having a conical contact surface 20, adapted to receive and contact with surface 19 on element 11. By this means I secure a maximum contact surface together with a steadying and aligning action of the lower end of rod 8. At the center of the conical opening in element 14, I provide a drilled depression 21 which prevents the tip of the element 11 from dubbing the center of the hollow and thus holding off full surface contact. This de pression also provides a clearance so that in case the surfaces should become oxidized, or pitted by arcing, they may be resurfaced by inter-grinding. I p

The locking ring 9 is held in place by screws 22. It is provided with a circular hole 23 adapted to receive and act as a guide for rod 8. Oppositely positioned recesses 24 are formed on either side of this hole shaped to receive the lugs 7 Between these openings and on the upper face of ring 9 the notches 25 are formed adapted to engage lugs 7 My tong is operated y inserting weldin Its sides are Figure 1, for the purpose of illustration, shows my tong in disconnected position.

- Lugs 7 rest in notches 25 and the contact elements 11 and 14 are separated. All metal parts of the tong are therefore dead and the device may be laid anywhere about the work without fear of short circuit.

It is to be understood that the lower edges of lugs 7 are smoothly rounded and that notches 25 are shaped to receive them having suflicient depth so that when the tongs are in disconnected position any ordinary jar will not dislodge the lugs from these notches. Handle 10 and ring 16 are made of insulating material such as fiber or bakelite while all other parts are of suitable metal.

While my device may be generally considered a switch, I prefer to consider it an improved welding tong, wherein means for disconnecting the live exposed metal parts is provided. A switch usually operates to open and close an electrical circuit, whereas my device is used rarely, if ever, to close or break the circuit. It is properly used to disconnect the welding bar tongs from the live lead after the bar has been taken from the work.

Since it is conceivable that various structural modifications might be made within the scope of my invention, I desire to be limited only by the following claims.

I claim 1. In a device of the kind disclosed, in combination, a welding bar tong supported on a conductor bar having a contact element at its lower end, an insulating handle containing a contact element adapted to engage said contact element on said conductor bar and having means of attachment to a power cable, a spring normally holding said contacts together, and disconnecting means comprising a plurality of lugs on said conductor bar and a locking ring having recesses adapted to admit said lugs whereby said contacts are enabled to be forced together by said spring, and notches intermediate said recesses on the upper face of said ring adapted to'receive said lugs whereby said conductor and contact element supported thereon is held apart from said contact element in said handle, substantially as described.

2. In a device of the kind disclosed, in combination, an insulating supporting handle having at its upper end a guide ring, said guide ring having a centrally positioned round guide hole, and oppositely positioned openings on either side thereof adapted to receive lugs, a tong adapted to hold a welding bar and having, at its lower end, a flange and a downwardly extending guide rod terminating in a conical electrical contact element, said flange having oppositely disposed lugs on its under side adapted to enter the openings on either side of the center hole of said guide ring, a fixed electrical contact element secured in the lower end of said handle having a conical recess in its upper end and adapted to make contact with the electrode on the lower end of said guide rod, together with means for attachment to an electrical power cable, and a spring surrounding said guide rod within said handle adapted to force said contacts together, substantially as described.

3. In an electric welding tong, in combination, a welding bar tong, supported on a conductor bar having a contact element at its lower end, and an insulating handle containing a contact element adapted to engage said contact element on said conductor bar, and having means of attachment to a power cable, a spring normally holding said contacts together, and disconnecting means comprising a plurality of lugs on said conductor bar, and a locking ring having recesses adapted to admit said lugs whereby said contacts are enabled to be forced together by said spring, substantially as described.

4. In a device of the character disclosed, in combination, a tong member havin spring tensioned and manually adjustab e jaws adapted to receive and hold a welding bar comprising its upper portion, a conductive bar terminating in a contact surface comprising its lower portion and oppositely positioned lugs intermediate said upper and lower portions, a handle member comprising an insulated sleeve, a ring plate at its upper end having an opening adapted to receive that portion of the conductive bar on said tong element extending between and below said lugs and having recesses adapted to receive said lugs, and a stationary conductive element comprising a contact surface at its upper end adapted to cooperate with said contact surface on said tong member, and resilient means whereby said contact surfaces are normally held in contact, substantially as described.

55. In a device of the kind disclosed, in combination, a tong element consisting of a con ductive bar having spring actuated jaws adapted to hold a weldin bar on its upper portion, and having a conductive contact element at its lower end and intermediately positioned lug projections, a handle element having an insulated sleeve, and a retaining ringat its upper end, said ring having an opening adapted to receive the conductive bar on said tong element, and recesses ada ted to receive the lug projections on said con uctive bar, and having a contact member contained within said insulating sleeve, having a contact surface adapted to make electric contact with the conductive contact on said conductor bar, and on its outer portion, means for attachment to a conductor cable, and a spring operativeintermediate said handle element and said conductive bar whereby said lug projections are forced into said recesses in said retaining ring and the said contact elements thereby pressed into contact.

6. In a device of the kind disclosed, in combination, a tong element consisting of a conductive bar having spring actuated jaws adapted to hold a welding bar on its upper portion, and having a conductive contact element at its lower end and intermediately positioned lug projections, a handle element having an insulated sleeve, and a retaining ring at its upper end, said ring having an opening adapted to receive the conductive bar on said tong element, and recesses adapted to receive the lug projections on said conductive bar, and having a contact member contained within said insulating sleeve, having a contact surface adapted to cooperate to make electric contact with the conductive contact on said conductor bar and on its outer portion, means for attachment to a conductorcable, and a spring operative intermediate said handle element and said conductive bar whereby'said lug projections are forced into said recesses in said retaining ring and the said contact elements thereby pressed into contact, and means whereby said tong element may be raised against the pressure of said spring suflicient to separate said contact elements and fasten them in such raised position, substantially as described.-

7. In a device of the character described, in combination, a tong element consisting of a conductor bar having spring actuated jaws adapted to hold welding metal at its upper end, a contact element at its lower end, and lugs intermediately positioned, a handle element comprising an insulated sleeve handle having positioned therein a stationary contact element having means on its outer portion for connection to an electric power cable, a ring positioned in the upper'portion of said handle element having an opening adapted to receive the middle portion of said conductor bar, said opening having recesses adapted to receive the lugs on said conductor bar when in register, whereby said conductor bar is permitted longitudinal movement whereby contact with the contact element within said sleeve portion of said handle is made, said ring also having notches to receive said lugs when not in register with said recesses, whereby said contact elements are held apart, and spring means whereby bination, a handle element comprising an insulatin sleeve containing a contact element having an inwardly positioned contact surface and means for attaching a power cable, a relatively movable conductive bar with'tongs at its upper end, and a contact element at its lower end, a locking mechanism intermediate said conductive bar and said handle comprising lugs on said conductive bar, and an opening in the end of said handle element whereby said conductive bar may he forced against said contact within said handle element or locked out of contact therewith, and aspring-like element providing tension whereby said conductive bar is normally forced toward the contact in said handle, substantially as described.

9. An electric welding tong comprising in combination, an insulating handle having an electric contact conductor afiixed therein and provided with threaded attachment means for connection to a power cable, a ton element movable within the upper end 0 said handle having bar gripping jaws at its outer end adapted to contact with the contact conductor in said handle, a spring operative intermediate said handle and said tong elements adapted to normally hold said contact elements resiliently together, and latching means including lugs positioned on said tong element adapted to cooperate with recesses in said handle whereby when-in register the contact portion on said tong element may be moved against the contact in said handle, but when rotatively displaced out of register said contacts are held apart against the pressure of said spring.

CARLOS E. HALL.

said contacts are normally forced together,

substantially as described.

8. In a device of the kind disclosed, in com-

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